This invention relates to video recording, and more particularly, to a digital video recording system for use at Point of Sale (POS) locations, Automated Teller Machines (ATM's), and other locations where the monitoring of activities is important.
Video recording equipment is in common use throughout industry and commerce. Conventional video recording systems are analog systems employing a video recorder which records images on a magnetic tape. The recorder used is a slow scan recorder whose video input is provided by a camera located at the POS or ATM. Recording is typically continuous over a predetermined period which is typically 24 hours. If nothing of significance occurs during the recording period, the tape is simply rerun again through the recorder with the prior recorded images being recorded over.
This process has a number of problems associated with it. In most installations, most of the time, nothing ever happens. Rather, the same tape is used over and over with the same background image being recorded over and over. Only if something of significance happens is the tape removed and replaced. Preferably, each tape should be removed, degaussed, and reinserted in the recorder at the end of each recording interval. Or, each tape is changed every day with the tape removed being degaussed before its next use. However, this is seldom done because of the expense or impracticality of doing so.
Because the same images are continuously being recorded, over time, the magnetic particles in the tape tend to align themselves in a particular orientation consistent with those images. This residual magnetization degrades the resolution capability of the tape and resulting quality of the recorded images. One problem law enforcement officers or security personnel have with the recording systems described above is that the poor quality of the recorded images makes it difficult to discern features or details of the events captured on the tape, including the identification of persons.
Another problem with conventional recording systems is that simply because an event of significance has occurred, recording does not stop. Thus, in order to view the event, it is necessary to rewind the tape and scan through it to the place where the event is recorded. In situations where time may be critical, the resulting delay is very undesirable.